//---------------------------------------------------------------------------------
// Copyright (c) 2011, Microsoft Corporation
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//---------------------------------------------------------------------------------

namespace Microsoft.Samples.ServiceBus.WindowsPhoneChat.Commands
{
    using System;
    using System.Windows.Input;

    public abstract class Command<TParameter> : ICommand
    {
        public event EventHandler CanExecuteChanged;

        public virtual bool CanExecute(object parameter)
        {
            if (parameter is TParameter)
            {
                return this.CanExecute((TParameter)parameter);
            }

            return false;
        }

        public virtual void Execute(object parameter)
        {
            if (parameter is TParameter)
            {
                this.Execute((TParameter)parameter);
            }
        }

        protected abstract bool CanExecute(TParameter parameter);

        protected abstract void Execute(TParameter parameter);

        protected virtual void OnCanExecuteChanged(object sender, EventArgs e)
        {
            if (this.CanExecuteChanged != null)
            {
                this.CanExecuteChanged(sender, e);
            }
        }
    }
}
